Fair Market Value vs ready reckoner value

1) I had purchased a 1BHK flat  @ 1.75 Lakhs in 1988.

2) A valuer (Govt regd Valuer)  gave a certificate of Ready reckoner Price of  6,54,815   as on 1st April 2001.

3) My question is whether  FMV ( as termed in ITR-3)  is same as Ready Reckoner  price.

4) My Regd sale price in  june 2023 is 91 lakhs  and Ready reckoner price by dept  is 65 Lakhs.

5) Whether I can take fair market value of property in 2001 as approx 20%/30% more than  ready reckoner price